DE2138463A1 - Copolymer and process for its preparation - Google Patents

Description

47 845

Applicant: The Standard Oil Company, Midland Building, Cleveland , Ohio 44115 / USA

Addition to P 20 54 158.6 of November 4, 1970

Copolymer and process to his

The invention relates to a new process for copolymerization of styrene and alkyl-substituted styrenes with an olefinic nitrile in the presence of a conjugated one Diolefin elastomers. In particular, it relates to a method of making these materials — the superior one have physical properties ^ in high yields, through copolymerization of styrenes and acrylonitrile in the presence of an elastomeric diolefin polymer.

Copolymers of acrylonitrile and styrene are well known as described, for example, in "Vinyl and Related Polymers", C.A. Schildknecht, 1952, pages 49 to 54 can be seen. Graft copolymers of acrylonitrile and styrene or diolefin elastomers, in particular such Copolymer ©, the one

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containing a predominant proportion of styrene are also well known. The previously known copolymers of acrylonitrile and styrene and rubber-modified copolymers generally consist of a complex mixture of copolymers and homopolymers with different compositions of monomers. Such copolymers contain fractions which consist almost exclusively of acrylonitrile units and only have a few styrene units scattered along the chains. They also contain fractions with a high styrene content and fractions that contain styrene and / or acrylonitrile grafted onto the rubber. Copolymers of styrene with 15 to 30 % acrylonitrile were economically interesting a few years ago because some of these materials have higher softening temperatures, improved impact strength and greater rigidity than styrene homopolymers.

The polymers according to the invention, on the other hand, are products a process in which a relatively high molar ratio of the olefinic nitrile in the polymerization reaction to styrene or alkyl substituted styrene is maintained. The copolymer obtained, be it in the grafted one or the ungrafted portion, contains equimolar or greater than equimolar ratios of polymerized olefinic Nitrile to polymerized substituted styrene. The copolymers according to the invention have clearly overlapping

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physical properties compared to known rubber-reinforced Copolymers and homopolymers from each of the comonomers. The copolymers of the invention have more in addition, distinctly superior physical properties compared with blends of the homopolymers each of the monomers.

To the present invention suitable substituted styrenes include the core and in the side chain alkyl-substituted styrenes such as alpha-methyl styrene, alpha-Ithylstyrol, vinyltoluenes, vinylxylenes, isopropylstyrenes _s such as o-, m- and p-isopropylstyrenes, tert.-butylstyrenes ₉ as o = ₉ m- and p-tert-butylstyrenes, o-, m- and p-methyl-alpha-methylstyrenes and the like and mixtures of such compounds. Diene elastomers useful in the present invention include rubbery homopolymers and copolymers of conjugated dienes having from 4 to 6 carbon atoms such as 1,3-butadiene, isoprene, chloroprene, piperylene, and the like. One or more of these dienes can be copolymerized with monomers such as acrylonitrile, methacrylonitrile, styrene, alpha-methylstyrene, ethyl acrylate and the like. Most preferred conjugated dienes are 1,3-butadiene and isoprene and the most preferred comonomers for the elastomer are acrylonitrile, methacrylonitrile and styrene. The diene elastomers suitable according to the invention should contain 50% or more of the polymerized diene.

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Copolymers which have the desired properties are obtained when the molar ratio of olefinically unsaturated nitrile to substituted vinylaromatic compound in the monomer mixture is kept between about 5 i 1 and 200 s 1, preferably between 20-1 and 150-1, during the polymerization process. The copolymers of the invention finally obtained have a molar ratio of the polymerized olefinically unsaturated nitrile to polymerized vinyl aromatic monomers of about 1: 1 to 30: 1, preferably about 1.4-1 to 18-1, excluding the diene elastomer contained therein. The composition of the finally obtained copolymer is kept in the specified range by one of the following measures?

(1) Carrying out the copolymerization down to a low conversion or

(2) Carrying out the copolymerization up to a higher conversion, with during the course of the polymerization constantly fresh viny! aromatic monomer dem Polymerization mixture is fed. Process (2) is the preferred variant of the process. The proportion of Diene elastomer in the final polymer, varies between about 1 percent by weight and about 25 percent by weight Elastomer based on the total weight of the final polymer.

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The copolymerization of the monomers in the presence of the rubber can by heating in Mass ©, in an inert solvent, in emulsion or in dispersion in the form of droplets into an inert medium, for example as a suspension in water and at a temperature in the range of about ⁰ ° C. or less are ⁰ to about 100 C or above at atmospheric pressure, sub-atmospheric pressure od © r superatmospheric pressure performed. Because of the more convenient handling and recovery of the product obtained, an aqueous emulsion or suspension process in which the monomers are copolymerized in the presence of an emulsion or suspension of the preformed rubber is preferred.

Catalysts that can be used to Bopolymerisation of the olefinically unsaturated nitrile and the substituted vinyl aromatic monomers include the peracid catalysts, such as persulfuric acid, peracetic acid and perphthalic acid, persalts such as potassium persulfate, peroxide catalysts, such as hydrogen peroxide, benzoyl peroxide, Chlorbenzoylp @ roxyd _s Bromobenzoyl peroxide * naphthyl _{peroxide, acetyl peroxide, benzoyl acetyl peroxide 9} lauryl peroxide, succinyl peroxide, di-ter.-butylpepo2ryd ₉ dicumyl peroxide, cumyl hydroperoxide, tert.-butyl peroxide, tert.-butyl peroxide, & tert.-butyl peroxide, & tert. Azo compounds as catalysis

gates, such as azobisisobutyronitrile. If desired, can Mixtures of the polymerization initiators can be used. To initiate the polymerization, radiation, such as Ultraviolet rays, X-rays, nuclear rays and the like can be applied.

The polymerization can be carried out to completion without substantial interruption or can be carried out at any Point to be canceled shortly before completion. Incomplete polymerization can lead to the production of a Syrup-like mass are used, which are further worked up and, if necessary, essentially completely can be polymerized.

Unreacted polymerizable material can be separated from the polymer by any suitable method such as by filtration, extraction, distillation and the like. The polymerization can take place in an apparatus of any suitable type and carried out in a partial, semi-continuous or continuous manner will.

A particularly preferred method for the copolymerization is a polymerization process in aqueous emulsion, in which an aqueous emulsion of the monomer is polymerized in admixture with an aqueous latex of the elastomer and in addition styrene or a substituted styrene continuously to the reaction mixture for upright

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Maintenance of the desired monomer ratio is added during the course of the reaction.

Emulsifiers that can be used in the process of aqueous emulsion polymerization include soaps such as sodium and potassium myristate, laurate, palmitate, oleate, stearate, resinate and hydroabietate, alkali metal alkyl or alkylene sulfonates such as sodium » rad potassium lauryl sulfate, cetyl sulfate, alkyl sulfonate -gt © aryl _{sulfonate 9} sulfonated castor oil and the asamonium salts thereof, salts of higher amines such as laurylamine hydrochloride and stearylamine hydrobromide and materials with higher molecular weight such as sodium polyacrylate, methyl cell tilose and the like.

Suitable molecular weight modifiers, such as alkyl and aryl mercaptans, including n-dodecyl mercaptan, tert-dodecyl mercaptan and the like, in an amount from about 0 percent by weight to about 1.0 percent by weight based on the total weight of Monomer rubber-like material can be used.

A latex is usually obtained as the product of the aqueous emulsion polymerization. The copolymers can be made from the latex can be recovered by any suitable means, for example by coagulation with electrolytes or Solvents, freezing out and the like.

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Other modifiers, including plasticizers, stabilizers, Lubricants, dyes, pigments and fillers can be added during the polymerization process, provided that they do not react chemically with the constituents of the reaction mixture or these affect in other ways. Otherwise, this Modifying agents can be added following the polymerization. Examples of other modifiers and pigments that can be added are wood flour, wood fiber, paper dust, clay, glass wool, glass fiber, mica, Granite dust, silk flakes, cotton flakes, steel wool, Fabric, sand, soot, titanium dioxide, zinc oxide, lead oxide, chrome yellow, rubbers, oils, waxes and the like.

Other compounding additives, such as extenders, stabilizers, Dyes and the like can also be used in a known manner for the preparation of the compositions according to the invention as long as the balance between impact strength, flexural strength, tensile strength, processability, heat distortion temperature and the like is not affected to such an extent that the mass is no more than tough, rigid, thermoplastic product is suitable.

The thermoplastic resins obtained from those according to the invention Process produced copolymers are obtained, have many of the ideal properties of the thermo-

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plastic resins and show excellent at the same time Capability as gas and vapor barrier, very high heat deformation points, high tensile strength, high flexural strength, one high degree of hardness, remarkably high impact strength, solvent resistance and a low degree of Creep, properties that are otherwise more characteristic of thermosetting resins. Because of this excellent The resins made from the novel copolymers according to the invention can combine properties for numerous purposes can be used for which known thermoplastic resins and even thermosetting resins are completely unsuitable.

The compositions according to the invention have excellent processing properties and lzörm®n extruded, calendered, deformed, sucked, embossed, processed and otherwise treated in order to obtain colorless, translucent and in some cases transparent, valuable, rigid, impact-resistant products and objects that are excellent , have balanced chemical, physical and electrical properties.

The compositions according to the invention can advantageously be used for the production of all types of customary and usable extruded or shaped (by injection molding or compression molding) moldings, such as foils? Rods, tubes and the like, but they are grained, just as

rolled or calendered foils and the like are used that can be post-formed by vacuum deep drawing or similar processes. You can by incorporating foamed by blowing agents and heating. Foamed and non-foamed films can be made into a laminate get connected. The compositions according to the invention can be used for numerous purposes, for toughness and resistance against creep and deformation at elevated temperatures are required with great advantage instead the common rubber or plastic masses and even instead of metal, wood or other materials be used. The resins are particularly suitable for manufacture of objects and devices which are subjected to relatively high temperatures for a fairly long period of time need, like medical instruments and the like. Thus, the compositions according to the invention for the manufacture of machine parts, such as gears and cams, parts of textile machines such as bobbins, shuttles, grippers and the like, used to manufacture containers and pipelines, especially for chemical and similar processes where resistance to corrosive substances is desired. They can also be used for filter press plates and rotating drums for plates? processes, electrical parts, such as connection terminal valley lists, Telephones and protective housings for cable connections, as well as for charging boxes and trays, cases, radio housings, furniture,

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Records, signs, small boat hulls and decks, for Cladding or covering the walls and surfaces of buildings, automobiles or ships, including protective armor Protective suits, automobile parts such as "headlines", steering wheels, door panels and parts of seats, wheels of Roller skates, protective helmets, packaging materials for food, pharmaceuticals and cosmetics, including pressure bottles and the like. Containers, printing plates, tools, die cutting blocks, washing machine parts such as lids, baskets, bearings and Impellers and numerous other items as would be readily apparent to those skilled in the art.

The compositions according to the invention can, if desired, at the manufacture of said or other objects are laminated or otherwise reinforced, for example with fibers, fabrics or wire nets, although often the strength of these materials even without reinforcement is sufficient.

The invention is illustrated in more detail below by the following examples. X in these examples are the quantities of the components are given in parts by weight, unless otherwise stated.

example 1

A. An acrylonitrile-butadiene copolymer elastomer latex was made from the following components?

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2 0 9 8 oiTi 6 9 7 ——

- 12 - water 2138463 Latex had a total and styrene was in established: 1,3-butadiene Parts by weight solids content of 30.3 percent by weight. Presence of a portion of the latex A prepared above Parts by weight Acrylonitrile 200 B. A copolymer of acrylonitrile Use of the following components 1 419 tert-dodecyl mercaptan 70 6.3 Versene Fe-3 (41 % activity) 30th water 0.6 Soap flakes 0.65 GAFAC RE-610 * 0.5 Daxad * flakes 0.05 tert-dodecyl mercaptan 91.05 Azobi si sobutyronitrile 1.40 Azobisisobutyronitrile 8.95 0.10 Acrylonitrile 21.64 -13- 0.40 Styrene * Dispersant, sodium alkylnaphthalene sulfonate. Latex A The polymerization was carried out with continued stirring 50 ⁰ C for 15 hours in the practical absence of acid fabric carried out. The final one

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* Emulsifier, which is a mixture of RO- (CH ₂ CH ₂ O- ^ and [RO- (CH ₂ CH ₂ O- ^ _n I _£ Ρ0 ₂ Μ), where η is a number from 1 to 40, R is an alkyl or an alkaryl group, preferably a nonylphenyl group and M denotes a hydrogen atom, ammonium or an alkali metal The emulsifier is a product of General Aniline and Film Corporation.

The polymerization was conducted at 6O ⁰ C snter nitrogen with continued stirring. The molar ratio of acrylonitrile to styrene was 20% 1. During the two-hour polymerization period was added 39.6 parts of styrene is pumped at such a rate into the reaction mixture that the Monomerenmo! Ι ratio of acrylonitrile to styrene during the entire polymerization time is substantially constant at 20 1 remained . The molar ratio of acrylonitrile / styrene monomers in the reaction medium was determined by intermittent gas chromatographic analysis. At the end of the polymerization period, the mixture was coagulated with excess methanol. The polymer was collected by filtration and dried under reduced pressure. A total of 96.5 parts of the polymer (yield 65.2 %) was obtained. The polymer contained 11.9 % nitrogen, corresponding to a molar ratio of acrylonitrile to styrene of 1 _? 61 s 1. Seststäbe of the polymer were prepared by compression molding at atm 19O ⁰ C under a pressure of 393.7. The test sticks showed the following physical

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Kara characteristics: an ASTM heat distortion temperature of 95 C, a flexural strength of 1146 kg / cm (16.3 x 10 ³ psi), a flexural modulus of 27052.8 kg / cm (3.99 x 10 psi), a tensile strength of 696.04 kg / cm (9 _f 90 χ 10- ^ psi) and an Izod impact strength of 0.177 m.kg (1.28 foot pounds) per 2.54 cm notch.

The creep rate was determined on a polymer B test stick according to ASTM D-674. A curve of the creep modulus at 90 ^° C. under a load of 70.31 kg / cm (1000 psi) versus the logarithm of time was extrapolated to give a time to "failure" of 30 minutes. "Failure" has been arbitrarily defined as a creep modulus of 3515 kg / cm (0.5 x 10- ^ psi) or less.

C. Procedure B of this example was repeated using a conventional Polymerization Procedure in which all of the acrylonitrile and styrene were introduced into the polymerization reactor from the start. It was found that the polymer had a nitrogen content of 11.7 percent by weight, corresponding to a molar ratio of acrylonitrile to styrene of 1.55: 1. The polymer was obtained in a yield of 69.4 Ji. This polymer was molded by compression molding at 190 ° C and 393.72 atmospheres (5600 psig) *. The following physical properties were determined for these test bars:
* to test rods - 15 -

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An ASTM Wärmeverfonmangstemperatur of 86 ⁰ C ₉ a flexural strength of 759.32 kg / cm ² (11.8 χ 10 ³ psi), a flexural modulus of 26717 kg / cm (3.8 χ ^ 10 psi), a tensile strength of 235 , 52 kg / cm (3.35 x 10 ^J psi) and an Izod impact strength of 0.0415 m.kg (0.3 foot pounds) per 2.54 cm notch.

The creep rate was measured on a test rod for polymer C determined using the ASTM D-674 method. A void occurred in less than 30 minutes.

Example 2

A. The procedure of Example 1-B was used to prepare a copolymer of acrylonitrile and p-tert-butylstyrene in the presence of an acrylonitrile-butadiene elastomer latex. The following approach was used t

Parts by weight

Water 404 GAPAC RE-610 6.06

tert-dodecyl mercaptan 0 _y 6

Azobisisobutyronitrile 0.5

Acrylonitrile 89.25

p-tert-butyl styrene 10.75

Latex A from Example 1 10.0

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The molar ratio of acrylonitrile to p-tert-butylstyrene in the original monomer charge was 25 seconds. The polymerization reaction was carried out as in Example 1-B and an additional 56.7 parts of p-tert-butylstyrene was added to the reaction mixture over the 160 minute period Reaction time fed. It was found that by press forming test bars produced had this polymer has the following physical characteristics: an ASTM heat distortion temperature of 95 ° C, a flexural strength of 885.86 kg / cm (12.6 χ ΛΟτ psi), a flexural modulus of 23904 kg / cm ² (3.4 χ 10 * psi), a tensile strength of 569.5 kg / cm ² (8.1 χ 10 ³ psi), and an Izod impact strength of 0.594 kg.in (4 _S 3 foot pounds) per 2, 54 cm notch. A test bar made from this polymer was subjected to the ASTM D-674 test for creep rate at 90 ^° C. under a load of 70.31 kg / cm (1000 psi). The bar was found to have a time to failure of 45 minutes. This polymer was obtained in 65 % yield (09 parts) and

^w contained 9.56 % nitrogen, corresponding to a molar ratio of acrylonitrile to p-tert-butylstyrene of 1.72: i.

B. Procedure A of this example was repeated with the exception that all $ reactants were introduced from the beginning in the polymerization reactor. A total of 57.9 parts of the polymer (54.4 % yield) was achieved, which contained 7.42 % nitrogen.

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held. The nitrogen analysis corresponds to a Kolverhältnis acrylonitrile to p-tert-butylstyrene of 1.18: 1. press-molding test specimens prepared by this polymer resin showed the following physical properties: an ASTM heat distortion temperature of 94 ⁰ C, a flexural strength of 696.04 kg / cm ( 9.9 x 10 psi), a flexural modulus of 21092 kg / cm (3.0 1Q- ⁵ psi), a tensile strength of 492.15 kg / cm (7.0 χ 10 ^ psi) and a notched Izod impact strength of 0.05254 m.kg (0.38 foot pounds) per 2.54 cm notch. A test rod made from this polymer was subjected to the creep rate test according to ASTM D-674 at 90 G under a load of 70.31 kg / cm. The bar was found to have a time to failure of less than 1/2 hour.

Example 3

The procedure of Example 1-B was followed for the copolymerization of acrylonitrile and styrene in the presence of a styrene-butadiene copolymer latex «The following approach was used %

Weight tell ©

Water 419

GAFÄC RE-61Q 6.3

tert. - = Bod3 © yliB @ roaptfm 0.6

il 0.5

91 * 05

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Styrene
Styrene-butadiene rubber latex

8.95 10.8

The styrene-butadiene latex contained 60 % total solids and consisted of approximately 28 % styrene and 72 % butadiene. The polymerization was ^{carried out at 60 °} C. in a nitrogen atmosphere. The molar ratio of acrylonitrile to styrene at the time of introduction was 20 ί 1. A polymerization time of 130 minutes was maintained and during this time an additional 53 parts of styrene were added to the reaction mixture. A total of 117.5 parts of the polymer obtained in accordance with (73% yield), for which a nitrogen content of 11.19 weight percent was found a molar ratio of acrylonitrile to styrene in the polymer of 1.44 ι 1. By press molding this polymer obtained test bars showed the following physical properties ί ASTM heat deformation temperature 97 ° C, a bending

2 ^ 5

strength of 970.23 kg / cm (13.8 χ 10 ^ psi), a flexural modulus of 35857 kg / cm ² (5.1 x 10 ⁵ psi), a tensile strength of 576.52 kg / cm (8.2 χ 10 * psi) and a notched Izod impact strength of 0.5668 m.kg (4.1 foot pounds) per 2.54 cm notch. A test rod of this polymer was taken at 90 ° C

subjected to a load of 70.31 kg / cm to the creep rate test according to ASTM D-674. At the bar there was a time for Failure detected for 24 hours.

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Example 4

The procedure of Example 1-B was followed to to produce a copolymer of acrylonitrile and styrene in the presence of a polybutadiene rubber latex. It was uses the following approach:

Parts by weight water 419 GAFAC RE-610 6.3 tert-dodecyl mercaptan 0.6 Azobisisobutyronitrile 0.5 Acrylonitrile 91.05 Styrene 8.95 Polybutadiene rubber latex 1O ₁ JB

The polybutadiene rubber latex had a total solids content of 60 percent by weight. The molar ratio of acrylonitrile to styrene in the feed was 20/1. The polymerization was carried out at 60 ° C. in a nitrogen atmosphere. An additional 66 parts of styrene were added to the polymerization mixture over the two hour reaction period. The polymer was obtained in a yield of 66.5 % (115 parts). The following physical properties were determined on test bars made of this polymer by compression molding! ASTM heat distortion temperature 96 ° C, a flexural strength of 1Ο19Λ5 kg / cm ² (14.5 x 10 ³ psi

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a flexural modulus of 28826 kg / cm (4.1 10 ³ psi), a tensile strength of 689.01 kg / cm (9.8 χ 10 ^ psi) and an Izod impact strength of 0.0415 m.kg (0. 3 foot pounds) per 2.54 cm notch. A test rod from this polymer was conducted at 9O ⁰ C and a load of 70.31 kg / cm the test, the creep rate according to ASTM D-subjected 674th The bar was found to have a time to failure of 12 hours.

Example 5

A. The procedure of Example 1-B was followed to manufacture of an acrylonitrile-styrene copolymer in the presence of a nitrile rubber latex with a molar ratio of acrylonitrile repeated to butadiene from 35 ϊ 65. The following approach was used:

Parts by weight

Water 540

GAFAC RE-610 8

tert-dodecyl mercaptan 0.8

Azobisisobutyronitrile 0.6

Acrylonitrile 95.3

Styrene 4.7

Acrylonitrile butadiene latex (35/65) 13.9

The acrylonitrile-butadiene elastomer latex had a total solids content of 60 percent by weight. The polymerization was carried out at a temperature of 60 ° C in a nitrogen atom

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atmosphere carried out. The mole ratio of acrylonitrile to styrene in the feed was 40: 1. An additional 25.3 parts of styrene was pumped into the polymerization reactor over the 160 minute reaction period. A total of 89.3 parts (66.7 percent yield) of the polymer were obtained, which had a nitrogen content of 13.4 percent by weight. The nitrogen content of this polymer corresponds to a molar ratio of acrylonitrile to styrene of 2.02 ι 1. By press forming test bars made of this polymer th display the following physical characteristics: an ASTM heat distortion temperature of 92 ⁰ C, a flexural strength of 885.86 kg / cm ² ( 12.6 χ 10 ^ psi), a flexural modulus of 28826 kg / cm ² (4.1 χ 10 ⁵ psi), a tensile strength of 625.73 kg / cm ² (8.9 χ 10 ^ psi) and an Izod Notched impact strength of 0.345 m.kg (2.50 foot pounds) per 2.54 cm. A test rod of this polymer was ^{subjected to the ASTM D-674 test for the creep rate at 90 °} C. under a load of 70.31 kg / cm ^2. It was found that the rod had a time to failure of 6 hours. The water vapor and oxygen permeability were determined on thin disks of this polymer made by compression molding. There was a water vapor permeability of 9.9 g / 645 ^cm2 / 24 hrs / 0,025 mm at 25 ⁰ C. The oxygen permeability was added ^3/645 cm / found to be 5.4 cm / 24 Hrs / Ataosphäre 0.025 mm.

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B. Procedure A of this example was repeated with the exception that all of the constituents of the polymerization batch were fed to the polymerization reactor at the beginning. The polymer obtained in a yield of 71.7 % had a nitrogen content of 15.48, corresponding to a molar ratio of acrylonitrile to styrene of 2.7 J 1. Test bars of this polymer obtained by compression molding showed the following physical properties: An ASTM heat distortion temperature of 88 ° C, a flexural strength of 471.06 kg / cm (6.7 x 1Cr psi), a flexural modulus of 25311 kg / cm (3.6 χ 10 ⁵ psi), a tensile strength of 485.12 kg / cm (6, 9 x 1 Cr psi) and a notched Izod impact strength of 0.0304 m.kg (0.22 foot pounds) per 2.54 cm. A test rod of this polymer was subjected to the ASTM D-674 test for the creep rate ^{at 90 ° C. under a load of 70.31 kg / cm.} The rod had a time to failure of 30 minutes.

Example 6

The procedure of Example 1-B was repeated, around a copolymer of acrylonitrile and styrene in the presence of a nitrile rubber latex (weight ratio of acrylonitrile to butadiene of 35/65) using the following approach:

Parts by weight of water 552

GAFAC RE-610 8.3

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tert-dodecyl mercaptan 0.83

Acrylonitrile 97.61

Styrene 2.39

Acrylonitrile butadiene rubber latex 14.27

Azobisisobutyronitrile 0.64

The acrylonitrile butadiene latex contained 60 weight percent solids. The polymerization was carried out in the manner described in Example 1-B. A polymerization time of 270 minutes was maintained and an additional 16.95 parts of styrene were used during the polymerization period in order to maintain an essentially constant acrylonitrile-to-styrene monomer ratio in the polymerization mixture. The polymer was obtained in a yield of 48 % ( 60 parts) and it showed a nitrogen content of 15.0 percent by weight, corresponding to a molar ratio of acrylonitrile to styrene of 2.58: 1 in the polymer. Compression molded test bars of this polymer showed the following physical properties: an ASTM heat distortion temperature of 83.5 ⁰ C, a flexural strength of 653.85 kg / cm (9.3 x 1Cr psi), a flexural modulus of 19686 kg / cm ² (2.8 χ 10 "* psi), a tensile strength of 44293 kg / cm (6.3 x 1Cr psi), and a notched Izod impact strength of 0.608 m.kg (4.4 foot pounds) per 2.54 cm.

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Example 7

The procedure of Example 1-B was repeated to a copolymer of acrylonitrile and styrene in the presence of a nitrile rubber latex of Example 1-A with a Using total solids of 31.6 weight percent the following approach:

Parts by weight

Acrylonitrile 99

Styrene 1

Water 400

Alipal 4364 emulsifier

Nitrile rubber latex 31.6

tert-dodecyl mercaptan 3.5

Ammonium persulfate 0.06

The polymerization was carried out at about 50 ⁰ C and ätyrol was continuously added in such an amount that is sufficient to the initial acrylonitrile: styrene monomer ratio of 194: 1 to obtain upright. This ratio was determined by observing the monomeric composition in the polymerization mixture at intervals by gas chromatographic analysis. A total of 14 additional parts of styrene was necessary during the polymerization time of 270 minutes. It was found that the polymer obtained in a yield of 78.5%

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Contains 20.85 % nitrogen, which corresponds to an acrylonitrile: styrene molar ratio of 7.34: 1. The rubber phase of this product makes up about 11 % of the product. Compression molded test bars of this polymer exhibited the following physical properties: an ASTM heat distortion temperature of 97 ° C at 264 psi, a flex strength of 19,100 psi, a tensile strength of 13400 psi, a notched Izod impact strength of 1.5 ^{feet 1} pound / inch notch and a Brabender torque of 2800 grams (after 5 minutes).

It has also been found that films made from the polymer have an oxygen permeability of only 0.5 ecm mil /

100 inches / day / atmosphere.

The creep rate was determined on a test rod of this polymer using the flexural creep test, in which the load after 5 or 50 hours is calculated from the deflection in accordance with Federal Test Method Standard Nos. 406 and 1031; the values obtained are plotted against time on a logarithmic scale, giving a slope in inches / inches / log hour which represents the creep rate. The creep rate found in this way at 60 ^° C. and 300 psi was 0.018 %.

/ Claims;

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Claims (1)

Claims ι 1. Copolymer, characterized in that it is the in copolymerization product produced in an aqueous medium (A) a monomer mixture of acrylonitrile and Styrene with an acrylonitrile to styrene molar ratio of 5: 1 to 200: 1, and (B) represents a diene elastomer, in part A a molar ratio of bound acrylonitrile to styrene units of 1: 1 to 30: and 1 to 20 percent by weight of the diene elastomer B are contained. 2. Copolymer according to claim 1, characterized in that the diene elastomer is a homopolymer or copolymer is at least 50 percent by weight of a polymerized conjugated diene having 4 to 6 carbon atoms contains. 3. Copolymer according to claim 1 or 2, characterized in that the diene elastomer is a copolymer is made from 1,3-butadiene and acrylonitrile. Process for the production of a copolymer according to Claims 1 to 3, characterized in that in an aqueous medium a mixture of A acrylonitrile - 27 - 209808/1697 and styrene, the molar ratio of acrylonitrile to styrene of which is kept between 5: 1 and 200: 1 and B one Diene elastomer is polymerized until the final copolymer resin is 1 to 25 percent by weight of the diene elastomer B contains. • 5. The method according to claim 4, characterized in that the diene elastomer is a homopolymer or copolymer polymerize with at least 50 percent by weight of one conjugated diene having 4 to 6 carbon atoms is used. 6. The method according to claim 4 or 5, characterized in that the diene elastomer B is a copolymer of 1,3-butadiene and acrylonitrile is used. 7. The method according to claim 4 to 6, characterized in that the polymerization is carried out in the absence of oxygen at a temperature of about ⁰ ° C. to about 100 ^° C. in the presence of a free radical initiator. 209808/1697